My idea is to add an option to use the new dragonflight actionbar art, but with the old actionbar layout. Would probably need a few custom textures, which I'd be willing to help with.

Which old layout is that?

Shadowlands for example is not actually too different from DF, just a bit wider (12 buttons vs. 18).
Making the two book-ends further apart, or shrinking the buttons a bit to accomodate more would be relatively easy, as the buttons are generated individually, and not part of a big texture. Maybe I could even add an option to let users control the number of buttons in the DF Art.

Sorry I meant using the dragonflight art with the retail shadowlands layout.

I've made a prototype (currently overwriting the dwarf bar textures, my lua knowledge is limited) with DF's griffin endcaps and button backgrounds while also accommodating the extra reagent bag:

I have the art for the wyvern endcap done as well.

But thats not the Shadowlands layout. Shadowlands already moved the micro menu and the bags out of the actionbar cluster, like DF. Hence me asking.

Apologies for my confusion. I'm meaning to add DF art options to the Classic layout option in bartender, while making the reagent bag fit.

I think this looks better, I ditched the custom art textures and just used the dragonflight art from in the game:

It's just a copy of the art bar border, with 1 divider to separate the menu and bags, then the actionbar background with rgb set to 0.1 so it's not super dark and not transparent.